Circuit-interrupter



J. F. CAVANAGH.

CIRCUIT INTERRUPTER.

APPLICATION FILED Nov. I5. I9I.

'1313,856. Pafendmw. 19,1919.

I Ik 5y l @uw A TTOR/,VEKS

JOHN F. CAVANAGH, OF MERIDEN,

COBEORATION 0F CONNECTICUT.

CONNECTICUT, ASSIGNOR TELEPHONE & ELECTRIC COMPANY, INC., OF'MERIDEN,

TO CONNECTICUT CONNECTICUT, A.

CIRCUIT-INTERRUPTER.

Application led November 15, 1918.

To all 'whomc't may concern.'

Be 'it known that I, JOHN F. CAVANAGH, a citizen of the United States of America, residing at Meriden, Connecticut, have in'- vented a new and useful Circuit-Interrupter, of which the 'following is a specicati'on.

My present invention relates to the timing mechanism Jfor internal combustion engines and the objects of the invention are to provide a simple and ei'ectivecircuit interrupter construction which will be capable of high speed operation and which will retain its sufficiency even after long use.

The circuit interrupters now employed in distributer ignition systems have certain objections in common, some of the most serious of which, are the melting and oxidizing of the interrupter points which results in pitting and arcing, causing imperfect contact and the introduction of resistance in the primary circuit ete. Other faults arise from the fact that the interruptor points must be kept free of grease and oil, while the cam mechanism for vibrating the contacts should on the other hand, be well lubricated. These opposed requirements usually result in the insuiiicient lubrication of the mechanical vibrating mechanism and the consequent rapid wearing of these parts.

Another disadvantage of the prior art devices, is the frequent necessity for adjustment of the intcrrupter contacts to take up for the wear and the burning away of the contact points, which adjustments usually result in the contact points being put out of parallelism, which results in further uneven wear of the points.

In my invention I have avoided the objections mentioned and have provided a circuit interrupter which has'proved satisfactory in every respect by inclosing the interrupter contacts within a compartment and by eilecting the vibrations of the contacts through the medium of a flexible diaphragm forming one of the walls of said compartments.

forms, but I would have it understood that the invention may be embodied in other and Specification of Letters Patent.

Patented Aug. 19, 1919.

serial No. 262,641,

still different forms without departure from the true spirit and scope of the invention as defined in the appended claims.

In this drawing :d

Figure 1, is a cross sectional view of a cire cuit interrupter designed for a four-cylinder combustion engine. j

Fig. 2, is a plan View of the same.

Figs. 3 and 4 are sectional views of two other Vforms of the invention.

The interrupter contacts or points as they have been termed, are in the drawing designated 5 and 6 and are shown` furthermore as of ring construction to provide annular contacting faces, the central portion of such contacts being shown as hollowed y out or reduced as indicated at 7, vso as to cause the contacts to engage at their rims only.

The contact 5 as shown, is mounted in a relatively stationary support 8 of cupped construction to provide an open chamber and the cooperating contact 6 is shown as directly carried by a flexible diaphragm 9 closing the open side of the chamber and providing, with the support, a sealed chamber l0 for the break or gap between the contacts. j

The diaphragm 9 is usually constructed of spring material suoli as bronze or steel and tensioned so as to hold the contacts normally in engagement. In the illustration the diaphragm is clamped at its edges under the necessary tension by a ring 11 which may be spun over the metal of the cup-shaped support. The diaphragm is 'furthermore shown as insulated from the support by a suitable medium such as the insulating washer l2 interposed between the body of the support and the clamping ring.

The means for vibrating or iexing the diaphragm in a circuit open direction, consists in the present disclosure of a cam 13 having suitable connection with the dia* phragm. In connections consists of a lever 14- having a spring mounting 15 and connected with the diaphragm by extending the shank 1G of the upper contact loosely up through an opening 17 in the lever and Hanging it over at 18 to provide a shoulder for engagement by d il the lever as the lever is lifted by the cam points, rlhe lever is shown provided with a Wear-piece 19 for enga-gement with theV cam points, as customary in Vstructures ont this character. The vspring mounting for the lever is shown provided by forming a bend in the lever near the end thereof, the lever being supported for instance, by securing it directly to the base or support 8, as indicated at 20.

From the #foregoing it will .be clear that as the spring lever is lifted by the cam points, it will Gpick up the diaphragm through the connections described and thus periodicallyY eli'ect a separation of the interrupter contacts. As the break between the contacts is located entirely within the closed chamber, the oxidation is negligible. To absolutely eliminate oxidation the chamber may be exhausted more or less and in some instances I tind it desirable to introduce an inert gas such as nitrogen into the chamber. Yorking in this inclosed space, free from dust and other influences, the extent of separation between the contact points may be very slightand this enables the interrupter being operated at very high speed. The diaphragm maintains the movable contact in absolute parallelism with the relatively stationary contact and this, with the annular construction of the contacts produces practically perfect Contact between the points and avoids resistance losses, Wearing, etc. The lost motion connection described between the diaphragm and the operating means therefore, enables the separation of the contacts in parallel planes, and further enables the relatively movable contact to seat itself firmly against the fixed contact under the tension of the spring diaphragm.

In the modification illustrated in Fig, 3, the construction oi the contacts is varied to thc extent of mounting the lower Contact on a screw post '2i'. having an adjustable engagement in the screw seatin the base or support 8, said lower contact being in the forni oi. a flat head engaged at its rim lby the upstanding rini portion Qa oit the annular contact 25 'carried by the diaphragm. 4in this case, the cam maires direct engagement with the diaphragm which, for the purpose, is provided with a Wearing-piece 6 AFor engagement by the cam points.

lt will be obvious that in the rotation of the cam, the points thereon will depress the diaphragm and thereby elect a sepa-ration of the annular Contact elements within the sealed chamber. This construction maires it po Vile to relatively adjust the contacts, by tur ing the screw Joost oli the lower contact without unsealing the chamber.,

'The constrliicticn illustrated in Fig.. l is generally similar to the first form described, except that in this case the cam operates l the support and upon the diaphragm through the medium of an insulating push button 27 through an opening 28 in the supporting base 8 and engaging at its upper end with the diaphragm-carried Contact. This push button is shown mounted on a flexible diaphragm 29 secured to the support and form ing the rear wall of the sealed chamber, said button having a suitable wearing head 30 for working engagement by the cam points. ln the opvchamber when the contacts are sealed, this is quickly consuincdcand the contacts there` after operate in a substantially neutral atmosphere. Another advantage arising from the use or" the diaphragm is that any heat generated is quickly dissipated by the relatively wide expanse of thin metal presented by the diaphragm.

I claim l. In a. circuit interrupter, the combination of relatively separable contacts, a flexible spring diaphragm tensioned to hold said relatively movable contacts in engagement and means for flexing said diaphragm to accomplish the separation of said contacts.

2. ln a circuit interrupter, the combination or" relatively movable contacts, a spring diaphragm supportingone of said contacts and tensioned to hold the contacts normally engaged and means for periodically flexing the diaphragm to separate the contact carried thereby from the coperating contact.

3. ln a circuit interrupter, the combination with a support having a chamber, a spring diaphragm sealing said chamber, cooperating interrupter contacts carried by diaphragm respectively, said diaphragm being tensioned to normally hold the contacts engaged, and means for ei'- fecting the periodic lexure of said diaphragm.

l. ln a circuit interrupter, the combination with chambcred means having a leXi ble diaphragm for one Wall thereof, annular interrupter contacts engagingA only at their rim portions and located within the chamber aforesaid, one of said annular contacts being carried by the flexible diaphragm so as to conduct heat thereto and so as to be operated thereby, and means Jior flexing the diaphragm.

5. In a circuit interrupter, the combination with relatively separable contacts and a flexible diaphragm supporting one of said contacts, of means for periodically vibrating said diaphragm and a, 10st motion connection between said vibrating means and 5 the diaphragm. l f 6. In a circuit interrupter, the combination with relatively separablecontacts and a flexible diaphragm for operating the same, 0f means for periodically Vibratin said diaphragm and a 10st motion conneetlon be- 10 tween said vibrating means and the diaphragm.

JOHN F. CAVANAGH. 

